In a major breakthrough, a team of US researchers has confirmed that deposits of a protein called beta amyloid in the brain trigger Alzheimer's disease.

Researchers expect to screen thousands of volunteers ages 65 to 85, hunting those whose brain scans show they have a sticky build-up believed to play a key role in development of Alzheimer’s. Source: Thinkstock Images

“The question was, does the amyloid really cause the tangles because the tangles are what kill the nerve cells? And this is the first proof of concept in a human nerve cell system that it does,” lead study author Rudolph Tanzi, director of the genetics and ageing research unit at the Massachusetts General Hospital, was quoted as saying.

To reach the conclusion, researchers used a 3D culture with neural stem cells that carried the variants in two genes, the amyloid beta precursor and presenilin 1, which is found in early onset Alzheimer’s.

The 3D models in the lab created both plaques and tangles.

The discovery may revolutionise drug discovery for other neuro-degenerative disorders, researchers noted in a paper that appeared in the journal Nature.